Two major research projects are underway. One long-term project involves the study of the central regulation of body fluids as a 'model' homeostatic-motivational system. Our most recently published work indicates that the theory that the subfornical organ in the dorsal 3rd ventricle houses the exclusive central receptors for angiotensin's dipsogenic actions is untenable. A site in or by the anterior ventral 3rd ventricle is capable of supporting a full dipsogenic response to angiotensin in the absence of (or during depressed function of) subfornical organ tissue. A technique which permits temporary plugging of specific ventricular compartments is providing of value in isolating focal areas of central responsiveness to angiotensin actions. A second research direction involves following-up the discovery in our laboratory that pinching a rat's tail (conceptualized as a mild stress) preferentially releases consummatory behaviors such as eating, copulation and even care of pups in the presence of appropriate stimuli. We are doing a pharmacological analysis of these phenomena, as well as comparing them to equivalent states of readiness to respond (and switch responses) during electrical stimulation of some brain regions. The nigrostriatal dopamine system seems crucial to the above phenomena, and it is of considerable interest that sustained or oft-repeated tail pinch can both reverse the aphagia which follows severe lateral hypothalamic lesions and can lead normal rats to over eat to obesity. We intend to continue to explore these avenues of study, and to extend the work to an analysis of interactions between functional neurochemical pathways in mediating both normal and abnormal behaviors. BIBLIOGRAPHIC REFERENCES: Fisher, A.E. and Buggy, J., Central mediation of water and sodium intake: A dual role angiotensin, presented at the International Symposium on Thirst, Lugano, Switzerland, October 1973 by Alan E. Fisher: In: Control Mechanisms of Drinking; Eds. G. Peters, J.T. Fitzsimons and L. Peters-Haefeli; Springer, Verlag, 1975, p 193-147.